Best Flea Killer Spray & Treatment For The Yard

  • Written By Dan Edwards on April 13, 2018
    Last Updated: December 10, 2020

Fleas in the yard can represent a challenge for pet owners. Not only are flea bites painful and irritating for you and your pet, they can also cause infections and spread disease. No matter how thoroughly you treat your home and your pet against fleas, if you do not treat your outside spaces, the pesky fleas will be back and biting in no time.

Luckily, there are a number of flea yard treatments available which can help you to eliminate these pests for good. In this article, we discuss how flea spray works, which are the best flea sprays, and how to use them safely.

How Does Flea Spray Work?

If you’ve recently treated your home and pet for fleas, you could be forgiven for thinking you are now safe from these pests. Unfortunately, if your home has a yard, it is very likely you have unwittingly overlooked the root cause of the infestation.

Fleas make it into your yard from stray animals and other urban wildlife which visit when foraging for food. Foxes, opossums, raccoons, and cats are some of the creatures which travel through urban areas at night, leaving flea eggs behind them. Once these eggs hatch and develop into adult fleas, it will not be long before they hitch a ride on your pet and into the home.

Outdoor flea sprays are an effective way to tackle the source of your flea problem. They use ingredients which either kill or repel fleas on your property, ensuring that you and your pet are safe from a home pest invasion.

There are two kinds of yard flea sprays: those which use pesticides and others that don’t.

The most commonly used pesticide in yard flea sprays is “pyriproxyfen.” This is a form of insect growth regulator which acts in a similar fashion to insect hormones which are responsible for fertility and development.

Essentially, these growth regulators overwhelm the insect’s hormonal balance—which results in problems with egg production and physical growth. In the case of fleas, pyriproxyfen prevents flea larvae from developing into adults, as well as rendering female fleas infertile.

The use of pyriproxyfen is an efficient way of targeting areas where there is a high level of flea activity, such as under bushes, yard decking, and pet houses. In many cases, pyriproxyfen is used in tandem with an “adulticide” which directly kills the adult fleas rather than just making them infertile.

Insect growth regulators like pyriproxyfen are not immediate and foolproof solutions, though. Because they affect those insects which are young and developing, the user must understand the way a particular pest’s life cycle works to ensure efficient results.

If insect growth regulators are used in the absence of an adulticide, the results can take some time to become apparent. This is why adulticides are commonly used in combination with pyriproxyfen.

Most pyriproxyfen spray products are best used with a low-pressure spray hose. This is to keep an even application of the pesticide across the yard. If the spray is applied under too high a pressure, the soil could become dislodged and disturbed, resulting in an uneven distribution of chemical. The use of pyriproxyfen is also suitable for wood, concrete and metal structures.

An alternative to pesticide yard spray products is those which use natural oils to kill or repel fleas. One of the most common oils used is cedar oil.

Cedar oil works in two ways. Firstly, it’s known to be an effective insect repellent. Secondly, it can disrupt the life cycle of insects. Cedar oil dehydrates the target pests by extracting moisture from their bodies. It creates irritation to their breathing passages and interferes with the respiratory system.

Cedar oil also negatively affects the metabolism, nerve systems and general coordination of insects, which naturally makes feeding and reproductive activities much more difficult. The dehydrating properties can also kill flea eggs, larvae and pupae quickly.

Other commonly used oils are peppermint and clove extracts, which are also effective pest killers.

Best Flea Spray for the Yard

There is quite a wide variety of flea yard sprays on the market to choose from. Below we take a look at three of our favorite options:

Wondercide Ready-to-Spray Natural Flea Yard Spray

Wondercide flea spray comes in a convenient, ready-to-use container and is available in a range of concentrations.

This yard spray effectively repels and kills adult fleas, as well as numerous other pests such as ants, ticks and mosquitoes. It also attacks flea eggs, larvae and pupae, preventing them from reaching maturity and hatching.

The spray is suitable and safe for use near swimming pools, fish ponds, patios, lawns and kennels. It doesn’t cause any harm to beneficial yard insects like bees.

The active ingredient in the Wondercide formula is cedar oil. This oil works by blocking the action of a compound known as octopamine, which interferes with the heart rate and metabolism of fleas and other insect pests.

When these insects sense the presence of cedar oil, they will leave the area. If they are directly touched by it, they will die in a matter of hours. The advantages of the spray are:

  • Convenient and ready to use container
  • Natural formula
  • Pesticide free
  • Safe for use near ponds, kennels, swimming pools, etc
  • Both kills and repels fleas effectively

Bayer Animal Health Advantage Yard and Premise Spray

The Bayer yard and premise spray is a pesticidal spray. It uses the insect growth regulator pyriproxyfen, as well as an adulticide, to kill adult fleas and halt the growth of fleas in other stages of their life cycle.

It effectively prevents a flea infestation in the home by eliminating the source of fleas in yard areas. It will also kill ticks, which have the potential to carry diseases transferable to humans.

The spray bottle is very easy to attach to a hose and can treat an area up to 16,000 square feet. The formula can be used around the perimeter of the home, on lawns, under bushes and shrubbery, and on patios and decking.

It should not be used near pools, ponds, pet beds or play areas. The combination of an adulticide and a growth regulator is a very quick and efficient way to hit fleas hard and wipe out the population rapidly. Brief benefits of the Bayer spray are:

  • Uses a combination of adulticide and insect growth regulator
  • Kills adult fleas and also halts development of eggs, larvae, and pupae
  • Will also eliminate ticks
  • Can treat up to 16,000 square feet with one bottle
  • Easily attached to yard hoses

Vet’s Best Flea and Tick Yard & Kennel Spray

Vet’s yard and kennel spray uses a combination of essential oils to kill and repel fleas, ticks, and mosquitoes. The formula is free from pesticides and is safe for both pets and children.

A bottle of this spray is able to treat an area of up to 4,500 square feet easily. It can be effectively used on grass lawns, turf, decking, concrete and asphalt surfaces. It uses a formula which combines peppermint oil and eugenol oil, which is derived from cloves.

These oils both smell great, and are effective in killing fleas upon contact, as well as repelling any which are hiding out of reach.

Because this spray is natural, it is perfectly safe and non-damaging to flowers, shrubs, and trees. Furthermore, the spray has the added benefit of eliminating mosquitoes from your yard, so you can enjoy your outside space without fear of pesky bites. The spray’s effectiveness includes:

  • Pesticide-free formula
  • Can treat an area of around 4,500 square feet
  • Safe for all surfaces
  • Uses peppermint and eugenol oils
  • Kills fleas and tick on contact
  • Repels remaining pests, including mosquitoes

How to Use Flea Spray Effectively in the Yard

Fleas like to hide in damp, dark, cool and shady areas of the yard. Their favorite spots are under bushes, shrubs and dense trees. They will not hide anywhere that has direct sunlight.

If you’re looking for signs of fleas in your yard, the best places to start are those which any pets like to frequent. If your dog or cat has favorite places to lie, dig, play or sleep, then these are the most likely places to find evidence of fleas. Also, well-sheltered areas such as under decking, yard furniture, the base of fences and outdoor pet houses are prime locations.

The very first step before treating your yard with flea spray is to tidy it up. Flea larvae are very phobic of light and adult flea eggs are often deposited in dense, sheltered areas where animals forage. Remove any old outdoor furniture that is never used.

Rake up loose leaves and debris, and use a brush to clear away any other plant material which could harbor fleas. If you have wood piles, carefully move them to another area. By tidying your yard, you not only make treatment more effective, you also eradicate common flea hiding places in the meantime.

An important note is that all flea yard sprays have specific directions depending on the formula they contain. They will also clearly state any safety warnings which must be adhered to. In fact, it is a violation of federal law to use pesticides in a manner contrary to the directions provided.

Almost all flea sprays will either come with an attached pump or an easy way to connect the bottle to a hose. These treatments are designed to be used by homeowners, but if you feel uncomfortable, you can always hire a professional to apply the treatment for you.

It is best practice to wear protective clothing, a face mask and a pair of gloves if you are treating the yard yourself.

If you are using a pesticidal spray, it’s advised to remove any children’s or pets’ toys before spraying. Keep your animals and children away from the treated areas to allow them time to dry.

If the directions say to keep them away for longer, do not ignore this advice. Sometimes, the directions will state to repeat the treatment in a few weeks, depending on the ingredients used.

Some states have individual regulations regarding minimum distances from watercourses when using insecticides. If you’re unsure, you will be able to find this information online.

Below is some generalized application advice when using yard flea sprays:

  • Do not apply yard sprays directly to animals
  • Keep children and pets away from treated areas until they have dried, unless otherwise advised
  • Do not water the areas treated heavily enough to produce run-off
  • Do not apply sprays when it is raining
  • Do not apply sprays into drains, sewers, gutters, or anywhere it may flow to a body of water
  • Do not apply flea sprays via a lawn misting system
  • Do not apply higher than 3 feet on buildings

Flea Spray Risks and Precautions

Pyriproxyfen is a chemical pesticide which interferes with the hormones of pests. It has a low toxicity level to humans and prevents insects from reproducing and developing. Pyriproxyfen is generally nontoxic to mammals, bees, and garden birds, but it can be very toxic to fish.

Pyriproxyfen has a low acute toxicity for all methods of entry into the body. It is not toxic if swallowed, but is slightly toxic if breathed in or upon contact with bare skin. It will not cause skin irritation, but can be irritating to the eyes. A dose of pyriproxyfen is unlikely to cause any negative health effects to people and this advice extends to children.

The World Health Organization (WHO) classifies pyriproxyfen as a “U” for toxicity; this means it is unlikely to cause a threat to health during normal use.

When flea sprays which use pyriproxyfen are used outdoors as intended, there is the potential that it will have unintended effects on other non-pest insects and arthropods. It can also negatively affect the development and reproduction of insects which may be natural predators of fleas.

One yard insect which many people worry about is bees. Pyriproxyfen is not toxic to bees. Studies have shown that bee colonies continue to behave and develop as expected after being fed a solution which contains pyriproxyfen.

Once pyriproxyfen has been applied to the soil, it doesn’t remain there for very long. After a few days, the chemical will have dissipated as a result of aerobic degradation.

After this initial rapid degradation, it will break down more slowly. Pyriproxyfen can have detrimental effects on the microbes present in soils, which if used repeatedly can affect soil quality.

Alongside pyriproxyfen, adulticides are often used. These are the pesticides which kill adult fleas immediately. A common adulticide is “esfenvalerate,” which is used in the Bayer Animal Health Advantage Yard and Premise Spray. Esfenvalerate is a type of pyrethrin pesticide.

These chemicals have a generally low toxicity to humans, but should still be treated with care. If esfenvalerate gets onto the skin, it can cause irritation, numbness, and tingling. If it gets into contact with the eyes, esfenvalerate cause burns, tearing, irritation, blurred vision, and scratches to the eye surface. If inhaled, there is the potential for irritation of the respiratory passages, causing coughing, runny nose, wheezing, and in some cases, difficulty breathing.

If dogs or cats ingest esfenvalerate they can experience tremors, drooling, seizures, difficulty breathing, convulsions, and exhaustion. If you have any reason to suspect poisoning of a child or pet, contact emergency help immediately. The animal poison hotline is (888) 426-4435.

With regard to the natural flea sprays, these are generally less hazardous than the use of pesticides, which is to be expected. Cedarwood oil is used in a number of topical beauty treatments and remedies, as well as vaporizers and home fragrances. Cedar oil is not classified as a toxic substance or as a pollutant.

The use of other essential oils and plant extracts in flea spray products, such as peppermint oil and citronella, is very safe. Of course, it is not advised to ingest these oils, but there is no risk of toxicity as long as they are used correctly.

With any flea product, always diligently follow the directions provided. Read the label thoroughly and call the helpline should you have any queries or concerns.

Always wash hands well after use, never apply directly to pets, and do not use if you’re pregnant or breastfeeding. As long as you follow the directions closely and use common sense, flea yard sprays are safe and effective treatments to rid your yard of pests.


The yard can be a hot spot for fleas, which will quickly leap aboard you or your pet and hitch a ride into your home. Once fleas have found their way inside, they can multiply incredibly fast, causing a troublesome infestation which brings irritation and distress to all residents.

It’s easy to overlook the yard as an area to treat for fleas. After all, it is very rare that you will spot fleas as readily in the yard, as you do when you see one leaping across your couch. Fleas are talented at hiding away in shady outdoor spaces, so the problem may not be obvious at first.

Using a yard flea spray is the best and most effective way to crush fleas at their source, protecting your home and pets from this blood-sucking menace. With both chemical and non-chemical options to choose from, you are sure to find a perfect flea yard spray for your needs.